Combination motor pneumatic driven train brake pipe pressure exhaust valve

ABSTRACT

A microprocessor controlled valve system is used with an EOT unit on a railcar remote from the locomotive of the train. The system includes a pressure transducer, a microprocessor unit, a valve device, a motor drive and a pneumatic drive. The microprocessor unit receives from the transducer an electrical signal indicative of actual brake pipe pressure and from the locomotive a brake command signal indicative of desired brake pipe pressure. The microprocessor unit issues a drive signal when the brake command signal requires a service brake application and an actuating signal when the brake command signal requires an emergency brake application. The valve device defines an elongated bore, a primary passage, a branch passage, an exhaust passage and an elongated valve body able to move reciprocatingly in the bore according to the operation of the drives. The primary and branch passages communicate with the brake pipe, and all of the passages communicate with the bore. The elongated valve body features (A) a first valve that when opened allows at least partial communication between the primary and exhaust passages and (B) a second valve that when opened allows communication between the branch and exhaust passages. The motor drive opens the first valve in response to and to the extent dictated by the drive signal. In response to the actuating signal, the pneumatic drive fully opens the second valve thereby fully opening the first valve so that pressure in the brake pipe flows through the valves and vents via the exhaust passage.

This application is a divisional application of U.S. application Ser.No. 08/831,485, filed Mar. 31, 1997, now issued as U.S. Pat. No.5,881,768 on Mar. 16, 1999.

CROSS REFERENCE TO RELATED APPLICATIONS

The invention taught in this patent application is closely related tothe inventions taught in two co-pending patent applications, namely: ATRAIN BRAKE PIPE PRESSURE EXHAUST CONTROL SYSTEM AND REGULATING VALVETHEREFOR, Ser. No. 08/562,961, filed Nov. 27, 1995; and PNEUMATICALLYDRIVEN TRAIN BRAKE PIPE PRESSURE EXHAUST VALVE, filed concurrentlyherewith and having Ser. No. 08/815,422. These patent applications areassigned to the assignee of the present invention and the teachingstherein are incorporated into the present application by reference.

FIELD OF THE INVENTION

The present invention, generally, relates to a valve for exhaustingpressure in the brake pipe of a railroad train consist at a locationremote from the locomotive concurrently with a brake valve regulatingservice reduction of brake pipe pressure at the locomotive. Moreparticularly, the invention pertains to a valve device that is motordriven for a service brake application and pneumatically driven for anemergency brake application.

BACKGROUND OF THE INVENTION

There is currently an ongoing effort in the railway industry to developelectro-pneumatic brakes for railroad freight trains. It is generallyacknowledged that such an electro-pneumatic brake control will enhancetrain operation by achieving a faster brake response, more equalized carretardation and a generally more uniform braking effort throughout along train of cars.

These improved results are based on the assumption that all of the cars,or at least a majority of the cars, making up a train consist will beappropriately equipped for such electro-pneumatic braking, in which casedirect braking cylinder pressure control is envisioned. With theexception of certain unit trains, however, it cannot currently bereasonably expected that any such majority of cars will be immediatelyimplemented with the required electro-pneumatic equipment.

Accordingly, for the present, indirect brake cylinder pressure controlis still extensively utilized. In this arrangement, the train brakingpipe pressure is controlled at the locomotive and also at one or severalremote cars throughout the train consist to accelerate reductions ofbrake pipe pressure in order to obtain a faster and more uniform brakeresponse.

Presently, railroad trains are required to carry an end-of-train unit onthe last car, which, among other functions, may be equipped toindependently and remotely initiate a reduction of brake pipe pressurefrom the rear of the train in response to the operator activation of aspecial triggering device disposed in the locomotive. This isaccomplished by transmitting an emergency brake activation commandsignal from the locomotive to the end-of-train unit via radiocommunication.

SUMMARY OF THE INVENTION

One approach to effecting such a brake pipe pressure reduction is toutilize a control valve having a variable orifice in which the brakepipe pressure is discharged through an orifice, the size of which isadjustable in proportion to the pressure reduction requirement. Thepresent invention, conversely, is predicated upon the use of amicroprocessor controlled valve system which features a valve device.The valve device is motor driven for purposes of a service brakeapplication and pneumatically driven for purposes of an emergency brakeapplication.

In essence, the present invention is intended to be incorporated into amore or less conventional radio control system for exhausting the trainbrake pipe pressure at the last car in accordance with service, as wellas, emergency brake application signals transmitted from the locomotive.In its broadest sense, the present invention uses the valve device toreduce the brake pipe pressure in the last car, or any selected car, ofthe train consist. The valve device has an valve means adapted todischarge or vent brake pipe pressure from such brake pipe when thevalve means is at least partially open. The rate of discharge is inproportion to the extent the valve means is open. The valve deviceincludes a motor drive means and a pneumatic drive means. The motordrive means is responsive to a signal for a service brake pipe pressurereduction to at least partially open the valve means. The pneumaticdrive means is responsive to a signal for an emergency brake pipepressure reduction to fully open the valve means.

In a more specific aspect of the invention, the valve device comprises avalve body having at least one supply passage to which the brake pipe isconnected, an exhaust passage open to atmosphere and a bore with whichthe supply passage and the exhaust passage are in communication. A valvemeans is disposed within the bore. The valve means reciprocates betweena closed position and a fully open position to selectively close, openand partially open the supply passage or passages to the exhaustpassage. An electric motor drive means is provided to partially andcontrollably open the valve means to thereby partially open the supplypassage to the exhaust passage, thereby venting brake pipe pressurepursuant to the signal for a service brake pipe pressure reduction. Apneumatic drive means is provided to quickly and fully open the valvemeans to fully exhaust the brake pipe pressure pursuant to the signalsfor an emergency brake pipe pressure reduction.

In an even more specific aspect of this invention, the valve devicecomprises a valve means having two supply passages to which the brakepipe is connected. Both of these passages are in communication with thebore on either side of the exhaust passage. A reciprocatible valve bodyincludes two valves. The first valve is adjustable and lies between afirst of the supply passages and the exhaust passage. The second valvelies between the second supply passage and the exhaust passage. Themotor drive means is adapted for micro adjustment of the reciprocatiblevalve body sufficient to selectively open the first adjustable valve tothereby controllably open the first supply passage to the exhaustpassage for service brake pipe pressure reductions, but not sufficientto open the second valve intended for emergency brake pipe pressurereductions. The pneumatic drive means is adapted for macro movement ofthe reciprocatible valve body to fully open the second valve to therebyfully open the second supply passage to the exhaust passage foremergency brake pipe pressure reductions.

OBJECTIVES OF THE INVENTION

It is, therefore, one of the primary objectives of the present inventionto incorporate in the end-of-train unit an electrically controlledpneumatic valve device for exhausting the train brake pipe pressure at alocation in a train consist remote from the locomotive in accordancewith service, as well as, emergency brake application signalstransmitted from the locomotive.

Another objective of the present invention is to provide a valve devicefor reducing the brake pipe pressure at a location in a train consistremote from the locomotive which has a relatively high degree ofreliability and ruggedness.

A further objective of the present invention is to provide a valvedevice for reducing the brake pipe pressure at a location in a trainconsist remote from the locomotive which utilizes an electric motor fora micro-controlled operation of regulating the valve device for aservice brake pipe pressure reduction and a pneumatic system for amacro-controlled operation of the valve device for an emergency brakepipe pressure reduction.

Still another objective of the present invention is to provide a valvedevice for reducing the brake pipe pressure at a location in a trainconsist remote from the locomotive, as in the foregoing, that issuitably sized for installation in the end-of-train unit disposed on thelast car of such train consist.

Still a further objective of the present invention is to provide a valvedevice for reducing the brake pipe pressure at a location in a trainconsist remote from the locomotive, as in the foregoing, which will notcause the railcar brakes to release in the event of a power failure.

In addition to the objectives and advantages described above, variousother objectives and advantages of the invention will become morereadily apparent to those persons who are skilled in the railway brakingart from the following more detailed description of the invention,particularly, when such description is taken in conjunction with theattached drawings and with the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a railroad train comprising aplurality of freight cars headed by a locomotive capable of radiocommunication with an end-of-train unit on the last car of the train;

FIG. 2 is a block diagram of a microprocessor based indirect brakecylinder pressure control system adapted for end-of-train service as canbe utilized in conjunction with the motor-pneumatic controlled valvedevice of this invention; and

FIG. 3 is a diagrammatic, cross-sectional view showing a presentlypreferred embodiment of the motor-pneumatic controlled valve device ofthis invention for carrying out the service and emergency reduction ofbrake pipe pressure in accordance with the indirect cylinder pressurecontrol system of FIG. 2.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

As illustrated in FIG. 1, railroad cars C_(N) of a train are physicallycoupled to a locomotive L by typical car couplers (not shown) and arefurther coupled pneumatically by a brake pipe BP that extendscontinuously from the locomotive L to the last car C_(NL). Associatedwith the last car in the train consist is an end-of-train unit EOT thatis coupled to the locomotive L via radio communication.

The last car C_(NL) of the train consist is further provided with abrake control valve device CV, as are all of the other cars C_(N). Brakecontrol valve devices CV are preferably an A.A.R. standard AB typecontrol valve, such as an ABD, ABDW or ABDX valve manufactured byWestinghouse Air Brake Co. As is well-known in the railroad art, thesebrake control valve devices CV operate to control the car brakes inresponse to variations of the train brake pipe pressure at therespective cars.

Referring now to FIG. 2, the end-of-train unit EOT includes amicroprocessor unit MPU. The microprocessor unit MPU is provided with afeedback signal from pressure sensor PS indicative of brake pipepressure and, also, a brake command signal 9 via radio transmission fromthe locomotive that operates the brake pipe pressure valve device 100which is the subject of this invention. Generally stated, the brakecommand signal 9 takes the form of either a service brake command signalor an emergency brake command signal.

The microprocessor unit MPU is programmed to compare the existing brakepipe pressure as represented by the signal from the pressure transducerPS to a given target pressure. This given target pressure is supplied tothe microprocessor unit MPU as the brake command signal 9 transmittedvia radio transmission from the locomotive. Through this signal, thelocomotive may command either a full reduction in brake pipe pressure tomake an emergency application of the brakes or something less than afull reduction in brake pipe pressure so as to make a serviceapplication of the brakes. The extent of the service brake applicationcan, of course, be conveyed in the brake command signal.

Pursuant to such operation, the microprocessor unit MPU will, inresponse to the service brake command signal, activate a motor drivemeans 12 to the extent necessary to achieve a requisite brake pipepressure reduction via valve 20. Additionally, such microprocessor unitMPU will, in response to the emergency brake command signal, open asolenoid operated valve 56 and thereby fully exhaust the brake pipepressure via emergency valve 22.

Each car C_(N), including the last car C_(NL), has its control valve CVconnected to brake pipe BP via a branch pipe 10. The control valve CV oneach car is associated with an auxiliary reservoir AR and an emergencyreservoir ER that are charged via brake pipe BP and provide a source ofcompressed air for operating the car brake cylinder device BC inresponse to service and emergency rates of reduction in the brake pipepressure.

The control valve device CV operates in response to increasing brakepipe pressure to charge both the auxiliary reservoir AR and theemergency reservoir ER to the operating pressure of such brake pipe BP,while concurrently venting the brake cylinder device BC disposed on thecar. Such operation is well-known to those skilled in the railwaybraking art, being known as "release and charging", and thus requires nofurther explanation.

In accordance with the embodiment illustrated in FIG. 3, the valvedevice 100, in the presently preferred embodiment of this invention,comprises a valve housing 30 with an elongated valve body 32reciprocatingly disposed within an elongated bore 34 centrally disposedwithin valve housing 30. A primary air supply passage 36, disposed in anupper portion of the elongated bore 34, extends into a receiving chamber40. Such primary air supply passage 36 is connected to the brake pipe BPvia branch pipe 38. Accordingly, receiving chamber 40 is normallycharged with compressed air at brake pipe pressure.

A branch supply passage 42 extends from the primary air supply passage36 to similarly maintain chambers 44 and 46 charged with compressed airat the brake pipe pressure. As is clearly illustrated, the chamber 46 isseparated from the chamber 48 by a diaphragm 50, while a small bypasspassageway 52 (about 1/16 inch diameter) is provided to generallyequalize the air pressure within the two chambers 46 and 48.

A significantly larger emergency exhaust passageway 54 extends fromchamber 48 with a solenoid-operated, spring returned, exhaust valve 56connected to the exit end thereof. In normal operation, i.e., in theabsence of an emergency brake application, such emergency exhaust valve56 is in a closed position, as is necessary to maintain the brake pipepressure within each of the respective chambers 44, 46 and 48.

As is further shown, the diaphragm 50 is attached to a valve stem 58,which extends from the elongated valve body 32, such that collapse ofdiaphragm 50 into the chamber 48 will cause such valve stem 58, andaccordingly the entire valve body 32, to be pulled in a downwarddirection as viewed in FIG. 3.

With further regard to elongated valve body 32, a cylindrical upper endportion 60 thereof is slidably disposed within a cylindrical sleeve 62which forms a part of the bore 34. In this manner, such cylindricalupper end portion 60 of the valve body 32 is adapted for reciprocatingmotion within such cylindrical sleeve 62. A receiving chamber 40, alsoforming a part of the bore 34, is provided below the cylindrical sleeve62. The receiving chamber 40 serves as a terminus portion of the primaryair supply passage 36. An O-ring seal 66 is, preferably, provided on thecylindrical upper end portion 60 to prevent escape of brake pipepressure from the receiving chamber 40.

A conical shaped valve 2O is provided below such receiving chamber 40which is intended to exhaust brake pipe pressure from the receivingchamber 40 for purposes of making a service brake application. As can beclearly seen in the drawing, such conical shaped valve 20 comprises amale conical valve head portion 70 circumferentially disposed on theelongated valve body 32 and is adapted to seat within a female conicalvalve seat 72 which also forms a part of the bore 34.

There is an O-ring seal 74 provided on such conical valve head portion70 to prevent escape of such brake pipe pressure from the receivingchamber 40 when valve 20 is intended to be closed. An exit chamber 76 isprovided below the valve 20 into which conical valve head portion 70recedes when the valve 20 is opened. Such exit chamber 76 is incommunication with an exhaust passage 78. Accordingly, when such conicalvalve 20 is even partially opened, air pressure within the receivingchamber 40 will pass into such exit chamber 76 and further pass from thevalve device 100 via the exhaust passage 78.

A reciprocatible piston-like element 80, forming a part of suchelongated valve body 32, is provided below the exhaust passage 78. Suchpiston-like element 80 is adapted for reciprocating motion within acylindrical portion 82 which forms a part of the bore 34. Here again, anO-ring seal 84 is, preferably, provided on such piston-like element 80to prevent escape of brake pipe pressure from such emergency exhaustchamber 44 which is disposed below the cylindrical portion 82.

A compression spring 86 is compressively disposed between the undersideof such piston-like element 80 and a flange 88 located at the base ofsuch bore 34. Such compression spring 86 is further disposed to encirclevalve stem 58 and serves to bias such valve body 32 in an upwardlydirection as viewed in the drawing.

The combination of such piston-like element 80, the cylindrical portion82 and the emergency exhaust chamber 44 serve to form a second valve,namely, the emergency exhaust valve 22, which is opened when piston-likeelement 80 moves downwardly sufficient to clear the lower edge ofcylindrical portion 82 to expose such exhaust chamber 44 to the exhaustpassage 78.

A motor drive means 12, containing a small electric motor 90, a geardrive assembly 92 and a gear driven element 94 is provided on the topportion of the valve housing 30. Activation of such electric motor 90will, through gear drive assembly 92, cause the gear driven element 94to be driven downward against the top of the cylindrical upper end 60,which forms a part of such elongated valve body 32. Accordingly, properactivation of such electric motor 90 in one direction will cause suchvalve body 32 to move in a downwardly direction, while activation of theelectric motor 90 in the other direction will permit the valve body 32to be returned in an upward direction by virtue of such compressionspring 86.

Pursuant to a normal operation, the brake pipe BP will be charged to thetrain operating pressure by movement of the locomotive brake valvehandle (not shown) to a release position in a manner which is well-knownin the railroad industry. The branch pipe 10 conducts compressed airfrom such brake pipe BP to each control device CV on each car C_(N)thereby charging each auxiliary reservoir AR and each emergencyreservoir ER and exhausting any compressed air in each brake cylinderBC.

Concurrently with the charging of the brake pipe BP, there is acorresponding radio signal transmitted to the EOT disposed on the lastcar C_(NL). Microprocessor MPU operates in response to this radio signalto move the electric motor 90 to its valve closing position and to closethe emergency solenoid valve 56. With electric motor 90 returned to itsvalve closing position, the compression spring 86 will then force thevalve body 32 upward thereby closing the valves 20 and 22.

When it is desired to make a service brake application, followingcharging of the brake pipe, the locomotive brake valve (not shown) isset in a position to achieve a reduction of the brake pipe air pressure.The degree of such brake pipe air pressure reduction corresponds to thedegree of service brake application desired. This reduction of suchbrake pipe air pressure constitutes a pneumatic signal that ispropagated through the train consist from front to rear via the brakepipe BP. Concurrently, according to a presently preferred embodiment ofthis invention, a service brake command signal is transmitted via radiofrom the locomotive to the end-of-train unit EOT which corresponds tothe reduced locomotive brake pipe air pressure.

Microprocessor unit MPU operates in response to this radio signal toenergize the electric motor 90 via a corresponding drive signal. Throughthe drive signal, the microprocessor unit MPU drives electric motor 90to the extent necessary to open the valve 20 and thereby reduce thebrake pipe air pressure to the target pressure, namely, the reducedlocomotive brake pipe air pressure. When this target brake pipe airpressure is achieved, the microprocessor unit MPU then causes theelectric motor 90 to be activated in the reverse rotation, therebywithdrawing the gear driven element 92 from the end of the valve body 32which will permit the compression spring 86 to at least partially closethe valve 20 and thereby maintain the target brake pipe air pressurewithin such brake pipe BP.

It should be apparent that the motor driven control will essentiallypermit rather fine, micro adjustment of the valve 20. In the presentlypreferred embodiment of the invention, such microprocessor unit MPUshould be programmed to, in essence, instantly commence opening of suchvalve 20 on demand and at a relatively high RPM of electric motor 90.However, as the air pressure within the brake pipe approaches the targetpressure, the speed of the electric motor 90 can be reduced in order toexactingly control the desired end point.

Likewise, when an emergency brake application is desired, themicroprocessor unit MPU receives the appropriate radio signal from thelocomotive and, in this case, the microprocessor unit MPU will energizethe solenoid operated exhaust valve 56 via a corresponding actuatingsignal. When the solenoid valve 56 receives this signal, solenoid valve56 energizes thereby quickly opening the valve 22. The compressed airwithin chamber 48 exhausts via the emergency exhaust passageway 54. Withthe compressed air in chamber 48 fully and quickly exhausted, thepressure differential on opposite sides of diaphragm 50 will cause thediaphragm 50 to collapse downward into chamber 48. This not only opensemergency valve 22, but also fully opens valve 20.

Specifically, by moving the valve body 32 downward to the maximumextent, such piston-like element 80 is caused to move below thecylindrical portion 82. This permits the pressurized air present inchamber 44 to be quickly exhausted via exit chamber 76 and exit passage78. At the same time, of course, the valve 20 is opened to its maximumextent.

While it may be observed that the chambers 46 and 48 are interconnectedby the bypass passageway 52, it was noted above that such bypasspassageway 52 should be rather small (approximately 1/16 inch diameteror less). The reason for the small diameter of passageway 52 is thatwhen such chamber 48 is exhausted for purposes of an emergency brakeapplication, the air pressure in chamber 46 should not also be exhaustedtherewith, but rather this air pressure must be at least momentarilymaintained for purposes of opening the valve 22, as described above.

Nevertheless, the air pressure within such chamber 46 will in time beexhausted concurrently with exhaustion of the air pressure withinchamber 44, so that the air pressure existing on either side of suchdiaphragm 50 will be rather quickly equalized, thereby permitting thecompression spring 86 to return the valve body 32 to its uppermostposition, thereby effectively closing both of the valves 20 and 22. Atthis point in time, however, essentially all of the brake pipe airpressure will be exhausted and the emergency brake application continueduntil the brake pipe air pressure is recharged, as above described.

As should be apparent from the above detailed description, a number ofmodifications and other embodiments could be incorporated withoutdeparting from the spirit of the invention. For example, a number ofdiffering pneumatic emergency valve controls could be devised.Therefore, while the detailed description presented above represents thepresently preferred embodiment of the valve and valve controlarrangement, it should be apparent that a great number of changes couldbe incorporated and varied embodiments could be devised by those personswho are particularly skilled in the railway braking art withoutdeparting from the scope of the appended claims.

We claim:
 1. A microprocessor controlled valve system for use in anend-of-train unit disposed on a railroad car at a location in a trainremote from a locomotive, said microprocessor controlled valve systemcomprising:(a) a pressure transducer for converting pressure existingwithin a brake pipe on such railroad car to an electrical signalindicative of such brake pipe pressure; (b) a microprocessor unit insuch end-of-train unit equipped for receiving from said pressuretransducer said electrical signal and from such locomotive a brakecommand signal indicative of such pressure desired in such brake pipesuch that said microprocessor unit issues a drive signal when said brakecommand signal indicates a service application of brakes of such trainis required and an actuating signal when said brake command signalindicates an emergency application of such brakes is required; (c) avalve device disposed in such end-of-train unit, said valve devicedefining an elongated bore, a primary supply passage, a branch supplypassage and an exhaust passage, said primary and said branch passages incommunication with such brake pipe and all of said passages incommunication with said elongated bore, said valve device including amotor drive means, a pneumatic drive means and an elongated valve bodyfor moving reciprocatingly within said elongated bore according to suchoperation of said motor and said pneumatic drive means, said elongatedvalve body featuring, (A) a first valve that when opened allows at leastpartial communication between said primary and said exhaust passages,and (B) a second valve that when opened allows communication betweensaid branch and said exhaust passages; (d) said motor drive means foropening said first valve in response to and to an extent dictated bysaid drive signal; and (e) said pneumatic drive means for fully opening,in response to said actuating signal, said second valve and therebyfully open said first valve so that such pressure in such brake pipeflows through said valves and vents via said exhaust passage.
 2. Themicroprocessor controlled valve system, according to claim 1, whereinsaid motor drive means includes an electric motor and a gear drivenelement actuated by said electric motor, said gear driven elementdisposed to engage said first valve such that said first valve can beopened in proportion to an extent to which said gear driven element ismoved by said electric motor.
 3. The microprocessor controlled valvesystem, according to claim 1, wherein said pneumatic drive meansincludes a solenoid operated and spring returned exhaust valve adaptedto quickly vent a brake pipe air pressure from said valves of said valvedevice.
 4. The microprocessor controlled valve system, according toclaim 2, wherein said pneumatic drive means further includes a diaphragmoperated piston-like member adapted to open and close said valves ofsaid valve device and said solenoid operated and spring returned exhaustvalve is adapted to vent such brake pipe air pressure from a chamberdisposed adjacent said diaphragm operated piston-like member to therebyactivate said diaphragm operated piston-like member to fully open saidvalves of said valve device.
 5. A microprocessor controlled valve systemfor use in an end-of-train unit of a railcar remote from a locomotive ina train, said microprocessor controlled valve system comprising:(a) apressure transducer for converting pressure within a brake pipe of suchrailcar to an electrical signal indicative of such brake pipe pressure;(b) a microprocessor unit in such end-of-train unit capable ofreceiving, (i) from said pressure transducer said electrical signal, and(ii) from such locomotive a brake command signal indicative of suchpressure that is desired in such brake pipe such that saidmicroprocessor unit issues, (A) a drive signal when said brake commandsignal indicates that a service application of brakes of such train isrequired, and (B) an actuating signal when said brake command signalindicates that an emergency application of such brakes is required; (c)a valve device in such end-of-train unit, said valve device defining anelongated bore, a primary supply passage, a branch supply passage, anexhaust passage and an elongated valve body for moving reciprocatinglywithin said elongated bore, said primary and said branch passages incommunication with such brake pipe and all of said passages incommunication with said elongated bore, said elongated valve bodyfeaturing, (A) a first valve that when opened allows at least partialcommunication between said primary and said exhaust passages, and (B) asecond valve that when opened allows communication between said branchand said exhaust passages; (d) a motor drive means for moving saidelongated valve body so as to open said first valve in response to andto an extent dictated by said drive signal; and (e) a pneumatic drivemeans for moving said elongated valve body so as to open fully, inresponse to said actuating signal, said second valve thereby fullyopening said first valve so that such pressure in such brake pipe flowsthrough said valves and vents via said exhaust passage.
 6. Themicroprocessor controlled valve system, according to claim 5, whereinsaid motor drive means includes an electric motor and a gear drivenelement actuated by said electric motor, said gear driven elementdisposed to engage said first valve such that said first valve can beopened in proportion to an extent to which said gear driven element ismoved by said electric motor.
 7. The microprocessor controlled valvesystem, according to claim 5, wherein said pneumatic drive meansincludes a solenoid operated and spring returned exhaust valve adaptedto quickly vent a brake pipe air pressure from said valves of said valvedevice.
 8. The microprocessor controlled valve system, according toclaim 7, wherein said pneumatic drive means further includes a diaphragmoperated piston-like member adapted to open and close said valves ofsaid valve device and said solenoid operated and spring returned exhaustvalve is adapted to vent such brake pipe air pressure from a chamberdisposed adjacent said diaphragm operated piston-like member to therebyactivate said diaphragm operated piston-like member to fully open saidvalves of said valve device.